Mobile terminal including display subjectable to bending deformation

ABSTRACT

A mobile terminal comprises a display unit that may be subjected to bending deformation in a first direction, and a rolling plate attached to a rear surface of the display unit, enabling bending deformation to correspond to bending deformation of the display unit, wherein the rolling plate includes a plurality of support bars extended in a second direction vertical to the first direction and arranged in parallel in the first direction, and an expanded side portion arranged at an end portion of the plurality of support bars, and the expanded side portion includes a guide bump engaged with its adjacent expanded side portion. Since the rolling plate supporting the display unit is not twisted by rotation, the display unit may maintain a flat state.

CROSS-REFERENCE TO RELATED APPLICATION(S)

Pursuant to 35 U.S.C. § 119 (a), this application claims the benefit ofan earlier filing date and right of priority to InternationalApplication No. PCT/KR2020/007357 filed on Jun. 5, 2020, the contents ofwhich are hereby incorporated by reference herein in its entirety.

BACKGROUND OF THE INVENTION Field of the Invention

The present disclosure relates to a mobile terminal, and moreparticularly, to a mobile terminal that has a flexible display and iscapable of extending a size of a screen while the display is scrolledand slid at the same time.

Discussion of the Related Art

Terminals may be generally classified as mobile/portable terminals orstationary terminals according to their mobility. Mobile terminals mayalso be classified as handheld terminals or vehicle mounted terminalsaccording to whether or not a user can directly carry the terminal.

A display device is a device having a function of receiving, processing,and displaying a video that a user may watch. For example, the displaydevice receives a broadcast selected by the user from broadcast signalstransmitted from a broadcasting station, separates a video signal fromthe received signals, and displays the separated video signal on adisplay.

In recent years, because of a development of a broadcasting technologyand a network technology, functions of the display device have also beenconsiderably diversified, and a performance of the device has beenimproved accordingly. That is, the display device has been developed toprovide not only broadcast contents but also various other contents tothe user. For example, the display device may provide game play, musiclistening, internet shopping, user customized information, and the likeusing various applications as well as programs received from thebroadcasting station. In order to perform such extended functions, thedisplay device may be basically connected to other devices or networksusing various communication protocols, and may provide the user with aubiquitous computing environment. In other words, the display device hasevolved into a smart device that enables connectivity to a network andcontinuous computing.

Recently, a flexible display having sufficient elasticity and capable oflarge deformation has been developed. The size of a mobile terminal canbe varied using the deformable nature of the flexible display. For themobile terminal having such a variable structure, changing the size ofthe mobile terminal should be stably performed, and there is a need fora structure to support the extended display unit to maintain a flatstate of the display unit.

SUMMARY OF THE INVENTION

Accordingly, the present disclosure is directed to a mobile terminalthat substantially obviates one or more problems due to limitations anddisadvantages of the related art.

One purpose of the present disclosure is to provide a mobile terminalthat may improve durability of a flexible display unit by notrestricting a point where the flexible display unit is bent to aspecific position.

To achieve these objects and other advantages and in accordance with thepurpose of the invention, as embodied and broadly described herein, amobile terminal comprises a display unit that may be subjected tobending deformation in a first direction, and a rolling plate attachedto a rear surface of the display unit, enabling bending deformation tocorrespond to bending deformation of the display unit, wherein therolling plate includes a plurality of support bars extended in a seconddirection vertical to the first direction and arranged in parallel inthe first direction, and an expanded side portion arranged at an endportion of the plurality of support bars, and the expanded side portionincludes a guide bump engaged with its adjacent expanded side portion.

The guide bump may include a guide protrusion protruded toward itsadjacent expanded side portion, and a guide groove arranged at anopposite side of the guide protrusion, corresponding to the guideprotrusion of the adjacent expanded side portion.

The guide protrusion may include a first contact surface vertical to thefirst direction, and the guide groove may include a second contactsurface that adjoins the first contact surface.

The guide groove may include a fourth contact surface that supports thethird contact surface of the guide protrusion in a thickness direction,and the fourth contact surface may form an angle of 90° or more with thesecond contact surface.

The third contact surface may include a curved portion extended from thefirst contact surface.

At least a portion of the end portion of the support bar may be exposedthrough the guide groove, and the exposed end portion of the support barmay be covered by the guide protrusion of the adjacent expanded sideportion.

The end portion of the support bar may include a fifth contact surfacethat adjoins the guide protrusion.

The mobile terminal may further comprise a first frame, a second frameslidably moving from the first frame to the first direction, switchedfrom a first state to a second state, and a slide frame moving to thefirst direction with respect to the second frame when the second framemoves to the first direction, wherein the display unit may include afirst area coupled to the first frame, a second area coupled to theslide frame, and a third frame arranged between the first area and thesecond area and bent to surround the second frame.

The second frame may further include a side portion arranged in thesecond direction, and a slid rail formed at the side portion, therolling plate may further include a slide hook protruded from theexpanded side portion and inserted into the slide rail, and the slidehook may move along the slide rail in accordance with the slide movementof the second frame, and may have an oblong shape longer in an extensiondirection of the slide rail than a width direction of the slide rail.

The expanded side portion may have a width that becomes narrow as it isspaced apart from the display unit.

The rolling plate may further include a non-expanded sheet coupled to arear surface of the plurality of support bars.

The non-expanded sheet may include a solid portion attached to theplurality of support bars, and a bending portion arranged between thesupport bars, wherein the bending portion may be inserted between thesupport bars during bending deformation.

The non-expanded sheet may include a metal material, and the bendingportion may have a mesh shape provided with a plurality of holes.

The mobile terminal may further comprise an adhesive tape for attachingthe non-expanded sheet to the support bar, wherein the adhesive tape maybe arranged in a position corresponding to the solid portion.

The mobile terminal may further comprise a rolling sheet arranged on therear surface of the display unit, wherein the rolling sheet may beprovided with a plurality of holes long in the second direction.

The mobile terminal may further include a flexible connector configuredto connect the support bars. The mobile terminal of the presentdisclosure may allow the size of the screen to be adjusted as needed,thereby satisfying both portability and usability.

Also, since the rolling plate supporting the display unit is not twistedby rotation, the display unit may maintain a flat state.

Also, since movement of the rolling plate in a thickness direction and athird direction is restricted, a state of the mobile terminal may stablybe changed.

Further scope of applicability of the present disclosure will becomeapparent from the detailed description given hereinafter. However, itshould be understood that the detailed description and specificexamples, while indicating preferred embodiments of the disclosure, aregiven by illustration only, since various changes and modificationswithin the spirit and scope of the disclosure will become apparent tothose skilled in the art from this detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure will become more fully understood from thedetailed description given herein below and the accompanying drawings,which are given by illustration only, and thus are not limitative of thepresent disclosure, and wherein:

FIG. 1 is a block diagram of a mobile terminal in accordance with thepresent disclosure;

FIG. 2 is a front view of a first state and a second state of the mobileterminal in accordance with an embodiment;

FIG. 3 is a rear view of the first state and the second state of themobile terminal in accordance with an embodiment;

FIGS. 4 and 5 are exploded perspective views of the mobile terminal inaccordance with an embodiment;

FIG. 6 is a side view of the mobile terminal as viewed from a thirddirection;

FIG. 7 is a view showing a driving unit of the mobile terminal inaccordance with an embodiment;

FIG. 8 is a cross-sectional view taken along lines A-A and B-B in FIG.2;

FIG. 9 is a view illustrating a display unit and a rolling plate of themobile terminal in accordance with an embodiment;

FIG. 10 is a view illustrating an issue raised in an extendable mobileterminal;

FIG. 11 is a cross-sectional view taken along lines C-C and D-D in FIG.2;

FIG. 12 is a cross-sectional view taken along lines E-E and F-F in FIG.11;

FIG. 13 is a view showing an expanded side portion and a guide hook ofthe mobile terminal in accordance with an embodiment;

FIG. 14 is a view showing an embodiment of the rolling plate of themobile terminal;

FIG. 15 is a view illustrating another embodiment of the mobile terminaland an expanded side portion of the rolling plate;

FIG. 16 is a view illustrating a problem that bending is formed in thedisplay unit of the mobile terminal;

FIGS. 17 to 19 are views illustrating an embodiment of the expanded sideportion of the rolling plate of the mobile terminal;

FIG. 20 is an exploded perspective view illustrating a layer structureof the rolling plate and the display unit of the mobile terminal;

FIG. 21 is a view illustrating a pattern of a non-expanded sheet and therolling sheet; and

FIG. 22 is a view illustrating a section of the layer structure of FIG.20.

DETAILED DESCRIPTION OF THE INVENTION

Description will now be given in detail according to exemplaryembodiments disclosed herein, with reference to the accompanyingdrawings. For the sake of brief description with reference to thedrawings, the same or equivalent components may be provided with thesame reference numbers, and description thereof will not be repeated. Ingeneral, a suffix such as “module” and “unit” may be used to refer toelements or components. Use of such a suffix herein is merely intendedto facilitate description of the specification, and the suffix itself isnot intended to give any special meaning or function. In the presentdisclosure, that which is well-known to one of ordinary skill in therelevant art has generally been omitted for the sake of brevity. Theaccompanying drawings are used to help easily understand varioustechnical features and it should be understood that the embodimentspresented herein are not limited by the accompanying drawings. As such,the present disclosure should be construed to extend to any alterations,equivalents and substitutes in addition to those which are particularlyset out in the accompanying drawings.

It will be understood that although the terms first, second, etc. may beused herein to describe various elements, these elements should not belimited by these terms. These terms are generally only used todistinguish one element from another.

It will be understood that when an element is referred to as being“connected with” another element, the element can be directly connectedwith the other element or intervening elements may also be present. Incontrast, when an element is referred to as being “directly connectedwith” another element, there are no intervening elements present.

A singular representation may include a plural representation unless itrepresents a definitely different meaning from the context.

Terms such as “include” or “has” are used herein and should beunderstood that they are intended to indicate an existence of severalcomponents, functions or steps, disclosed in the specification, and itis also understood that greater or fewer components, functions, or stepsmay likewise be utilized.

FIG. 1 is a block diagram of a mobile terminal in accordance with thepresent disclosure.

The mobile terminal 100 is shown having components such as a wirelesscommunication unit 110, an input unit 120, a sensing unit 140, an outputunit 150, an interface unit 160, a memory 170, a controller 180, and apower supply unit 190. Referring now to FIG. 1, the mobile terminal 100is shown having wireless communication unit 110 configured with severalcommonly implemented components. It is understood that implementing allof the illustrated components is not a requirement, and that greater orfewer components may alternatively be implemented.

More specifically, the wireless communication unit 110 typicallyincludes one or more modules which permit communications such aswireless communications between the mobile terminal 100 and a wirelesscommunication system, communications between the mobile terminal 100 andanother mobile terminal, communications between the mobile terminal 100and an external server. Further, the wireless communication unit 110typically includes one or more modules which connect the mobile terminal100 to one or more networks.

To facilitate such communications, the wireless communication unit 110includes one or more of a broadcast receiving module 111, a mobilecommunication module 112, a wireless Internet module 113, a short-rangecommunication module 114, and a location information module 115.

Regarding the wireless communication unit 110, the broadcast receivingmodule 111 is typically configured to receive a broadcast signal and/orbroadcast associated information from an external broadcast managingentity via a broadcast channel. The broadcast channel may include asatellite channel, a terrestrial channel, or both. In some embodiments,two or more broadcast receiving modules 111 may be utilized tofacilitate simultaneously receiving of two or more broadcast channels,or to support switching among broadcast channels.

The mobile communication module 112 can transmit and/or receive wirelesssignals to and from one or more network entities. Typical examples of anetwork entity include a base station, an external mobile terminal, aserver, and the like. Such network entities form part of a mobilecommunication network, which is constructed according to technicalstandards or communication methods for mobile communications (forexample, Global System for Mobile Communication (GSM), Code DivisionMulti Access (CDMA), CDMA2000 (Code Division Multi Access 2000), EV-DO(Enhanced Voice-Data Optimized or Enhanced Voice-Data Only), WidebandCDMA (WCDMA), High Speed Downlink Packet access (HSDPA), HSUPA (HighSpeed Uplink Packet Access), Long Term Evolution (LTE), LTE-A (Long TermEvolution-Advanced), and the like).

Examples of wireless signals transmitted and/or received via the mobilecommunication module 112 include audio call signals, video (telephony)call signals, or various formats of data to support communication oftext and multimedia messages.

The wireless Internet module 113 is configured to facilitate wirelessInternet access. This module may be internally or externally coupled tothe mobile terminal 100. The wireless Internet module 113 may transmitand/or receive wireless signals via communication networks according towireless Internet technologies.

Examples of such wireless Internet access include Wireless LAN (WLAN),Wireless Fidelity (Wi-Fi), Wi-Fi Direct, Digital Living Network Alliance(DLNA), Wireless Broadband (WiBro), Worldwide Interoperability forMicrowave Access (WiMAX), High Speed Downlink Packet Access (HSDPA),HSUPA (High Speed Uplink Packet Access), Long Term Evolution (LTE),LTE-A (Long Term Evolution-Advanced), and the like. The wirelessInternet module 113 may transmit/receive data according to one or moreof such wireless Internet technologies, and other Internet technologiesas well.

In some embodiments, when the wireless Internet access is implementedaccording to, for example, WiBro, HSDPA, HSUPA, GSM, CDMA, WCDMA, LTE,LTE-A and the like, as part of a mobile communication network, thewireless Internet module 113 performs such wireless Internet access. Assuch, the Internet module 113 may cooperate with, or function as, themobile communication module 112.

The short-range communication module 114 is configured to facilitateshort-range communications. Suitable technologies for implementing suchshort-range communications include BLUETOOTH™, Radio FrequencyIDentification (RFID), Infrared Data Association (IrDA), Ultra-WideBand(UWB), ZigBee, Near Field Communication (NFC), Wireless-Fidelity(Wi-Fi), Wi-Fi Direct, Wireless USB (Wireless Universal Serial Bus), andthe like. The short-range communication module 114 in general supportswireless communications between the mobile terminal 100 and a wirelesscommunication system, communications between the mobile terminal 100 andanother mobile terminal 100, or communications between the mobileterminal and a network where another mobile terminal 100 (or an externalserver) is located, via wireless area networks. One example of thewireless area networks is a wireless personal area networks.

The location information module 115 is generally configured to detect,calculate, derive or otherwise identify a position of the mobileterminal. As an example, the location information module 115 includes aGlobal Position System (GPS) module, a Wi-Fi module, or both. Ifdesired, the location information module 115 may alternatively oradditionally function with any of the other modules of the wirelesscommunication unit 110 to obtain data related to the position of themobile terminal. As one example, when the mobile terminal uses a GPSmodule, a position of the mobile terminal may be acquired using a signalsent from a GPS satellite. As another example, when the mobile terminaluses the Wi-Fi module, a position of the mobile terminal can be acquiredbased on information related to a wireless access point (AP) whichtransmits or receives a wireless signal to or from the Wi-Fi module.

The input unit 120 includes a camera 121 for obtaining images or video,a microphone 122, which is one type of audio input device for inputtingan audio signal, and a user input unit 123 (for example, a touch key, apush key, a mechanical key, a soft key, and the like) for allowing auser to input information. Data (for example, audio, video, image, andthe like) is obtained by the input unit 120 and may be analyzed andprocessed by controller 180 according to device parameters, usercommands, and combinations thereof.

Such cameras 121 may process image frames of still pictures or videoobtained by image sensors in a video or image capture mode. Theprocessed image frames can be displayed on the display unit 151 orstored in memory 170. In some cases, the cameras 121 may be arranged ina matrix configuration to permit a plurality of images having variousangles or focal points to be input to the mobile terminal 100. Asanother example, the cameras 121 may be located in a stereoscopicarrangement to acquire left and right images for implementing astereoscopic image.

The microphone 122 is generally implemented to permit audio input to themobile terminal 100. The audio input can be processed in various mannersaccording to a function being executed in the mobile terminal 100. Ifdesired, the microphone 122 may include assorted noise removingalgorithms to remove unwanted noise generated in the course of receivingthe external audio.

The user input unit 123 is a component that permits input by a user.Such user input may enable the controller 180 to control operation ofthe mobile terminal 100. The user input unit 123 may include one or moreof a mechanical input element (for example, a key, a button located on afront and/or rear surface or a side surface of the mobile terminal 100,a dome switch, a jog wheel, a jog switch, and the like), or atouch-sensitive input, among others. As one example, the touch-sensitiveinput may be a virtual key or a soft key, which is displayed on a touchscreen through software processing, or a touch key which is located onthe mobile terminal at a location that is other than the touch screen.On the other hand, the virtual key or the visual key may be displayed onthe touch screen in various shapes, for example, graphic, text, icon,video, or a combination thereof.

The sensing unit 140 is typically implemented using one or more sensorsconfigured to sense internal information of the mobile terminal, thesurrounding environment of the mobile terminal, user information, andthe like. For example, the sensing unit 140 may alternatively oradditionally include other types of sensors or devices, such as aproximity sensor 141 and an illumination sensor 142, a touch sensor, anacceleration sensor, a magnetic sensor, a G-sensor, a gyroscope sensor,a motion sensor, an RGB sensor, an infrared (IR) sensor, a finger scansensor, a ultrasonic sensor, an optical sensor (for example, camera121), a microphone 122, a battery gauge, an environment sensor (forexample, a barometer, a hygrometer, a thermometer, a radiation detectionsensor, a thermal sensor, and a gas sensor, among others), and achemical sensor (for example, an electronic nose, a health care sensor,a biometric sensor, and the like), to name a few. The mobile terminal100 may be configured to utilize information obtained from sensing unit140, and in particular, information obtained from one or more sensors ofthe sensing unit 140, and combinations thereof.

The output unit 150 is typically configured to output various types ofinformation, such as audio, video, tactile output, and the like. Theoutput unit 150 is shown having a display unit 151, an audio outputmodule 152, a haptic module 153, and an optical output module 154. Thedisplay unit 151 may have an inter-layered structure or an integratedstructure with a touch sensor in order to facilitate a touch screen. Thetouch screen may provide an output interface between the mobile terminal100 and a user, as well as function as the user input unit 123 whichprovides an input interface between the mobile terminal 100 and theuser.

The audio output module 152 is generally configured to output audiodata. Such audio data may be obtained from any of a number of differentsources, such that the audio data may be received from the wirelesscommunication unit 110 or may have been stored in the memory 170. Theaudio data may be output during modes such as a signal reception mode, acall mode, a record mode, a voice recognition mode, a broadcastreception mode, and the like. The audio output module 152 can provideaudible output related to a particular function (e.g., a call signalreception sound, a message reception sound, etc.) performed by themobile terminal 100. The audio output module 152 may also be implementedas a receiver, a speaker, a buzzer, or the like.

A haptic module 153 can be configured to generate various tactileeffects that a user feels, perceive, or otherwise experience. A typicalexample of a tactile effect generated by the haptic module 153 isvibration. The strength, pattern and the like of the vibration generatedby the haptic module 153 can be controlled by user selection or settingby the controller. For example, the haptic module 153 may outputdifferent vibrations in a combining manner or a sequential manner.

An optical output module 154 can output a signal for indicating an eventgeneration using light of a light source. Examples of events generatedin the mobile terminal 100 may include message reception, call signalreception, a missed call, an alarm, a schedule notice, an emailreception, information reception through an application, and the like.

The interface unit 160 serves as an interface with various types ofexternal devices that can be coupled to the mobile terminal 100. Theinterface unit 160, for example, may include any of wired or wirelessports, external power supply ports, wired or wireless data ports, memorycard ports, ports for connecting a device having an identificationmodule, audio input/output (I/O) ports, video I/O ports, earphone ports,and the like. In some cases, the mobile terminal 100 may performassorted control functions associated with a connected external device,in response to the external device being connected to the interface unit160.

The memory 170 is typically implemented to store data to support variousfunctions or features of the mobile terminal 100. For instance, thememory 170 may be configured to store application programs executed inthe mobile terminal 100, data or instructions for operations of themobile terminal 100, and the like. Some of these application programsmay be downloaded from an external server via wireless communication.Other application programs may be installed within the mobile terminal100 at time of manufacturing or shipping, which is typically the casefor basic functions of the mobile terminal 100 (for example, receiving acall, placing a call, receiving a message, sending a message, and thelike). It is common for application programs to be stored in the memory170, installed in the mobile terminal 100, and executed by thecontroller 180 to perform an operation (or function) for the mobileterminal 100.

The controller 180 typically functions to control overall operation ofthe mobile terminal 100, in addition to the operations associated withthe application programs. The controller 180 may provide or processinformation or functions appropriate for a user by processing signals,data, information and the like, which are input or output, or activatingapplication programs stored in the memory 170.

To drive the application programs stored in the memory 170, thecontroller 180 may be implemented to control a predetermined number ofthe components mentioned above in reference with FIG. 1. Moreover, thecontroller 180 may be implemented to combinedly operate two or more ofthe components provided in the mobile terminal 100 to drive theapplication programs.

The power supply unit 190 can be configured to receive external power orprovide internal power in order to supply appropriate power required foroperating elements and components included in the mobile terminal 100.The power supply unit 190 may include a battery, and the battery may beconfigured to be embedded in the terminal body, or configured to bedetachable from the terminal body.

Some or more of the components may be operated cooperatively to embodyan operation, control or a control method of the mobile terminal inaccordance with embodiments of the present disclosure. Also, theoperation, control or control method of the mobile terminal may berealized on the mobile terminal by driving of one or more applicationproblems stored in the memory 170.

FIG. 2 is a front view of a first state and a second state of the mobileterminal in accordance with an embodiment, and FIG. 3 is a rear view ofthe first state and the second state of the mobile terminal inaccordance with an embodiment. FIGS. 2(a) and 3(a) are views showing thefirst state in which the mobile terminal is contracted, and FIGS. 2(b)and 3(b) are views showing the second state in which the mobile terminalis extended.

As shown in the figures, the mobile terminal 100 in the first state isin a contracted position, and has a smaller size than the mobileterminal 100 in the second state. In addition, the size of the displayunit 151 positioned on the front of the mobile terminal 100 is alsosmaller than in the second state. The mobile terminal 100 in the firststate may be extended in a first direction D1 to switch to the secondstate. In the second state, as shown in FIG. 2(b), the size of themobile terminal 100 and the size of the display unit 151 positioned onthe front of the mobile terminal 100 are larger than in the first state,while the size of the display unit 151 positioned on the rear of themobile terminal 100 is reduced as shown in FIG. 3(b). That is, a part ofthe display units 151 positioned on the rear of the mobile terminal 151in the first state moves to the front of the mobile terminal 100 in thesecond state.

In the following description, the direction in which the mobile terminal100 and the display unit 151 thereof are extended or enlarged is definedas a first direction D1, and the direction in which the mobile terminalcontracts or retracts or is reduced to switch from the second state tothe first state is defined as a second direction D2. A directionperpendicular to the first and second directions D1 and D2 is defined asa third direction. Description will be made on the assumption that thefirst and second directions are horizontal directions and the thirddirection is a vertical direction. However, depending on the arrangementof the mobile terminal 100, the first and second directions may bevertical directions and the third direction may be a horizontaldirection.

As such, a flexible display unit 151 which is bendable may be used asthe display unit such that the position of the display unit may bevaried. The flexible display unit 151 may be a display unit capable ofmaintaining a flat state like a conventional flat panel display andcapable of warping, bending, folding, twisting, or rolling like paper.The flexible display unit 151 refers to a display which is manufacturedon a thin and flexible substrate and is thus lightweight and robust asnot to be easily broken. The flexible display unit according the presentdisclosure may be bent in a specific direction, and may be arranged suchthat the curvature thereof may change in the first direction.

In addition, an electronic paper is a display technology to whichproperties of general ink are applied. The electronic paper may bedifferent from the conventional flat panel display in using reflectedlight. The electronic paper may change information using a twisted ballor electrophoresis using a capsule.

In a state in which the flexible display unit 151 is not deformed (e.g.,a state of having an infinite curvature radius, hereinafter referred toas a basic state), a display region of the flexible display unit 151becomes flat. In a state in which the flexible display unit 151 isdeformed by an external force from the basic state (e.g., a state ofhaving a finite radius of curvature, hereinafter referred to as adeformed state), the display region may become a curved face. As shown,information displayed in the deformation state may be visual informationoutput on the curved face. Such visual information is implemented byindependently controlling light emission of sub-pixels arranged in amatrix. The sub-pixel refers to a minimum unit for implementing onecolor. When external force is applied to the flexible display unit 151,the flexible display unit 151 may be deformed to switch from the defaultstate, which is the flat state, to a bent state, which is not the flatstate.

The flexible display unit 151 may be combined with a touch sensor toimplement a flexible touch screen. When a touch is made on the flexibletouch screen, the controller 180 (see FIG. 1) may perform controlcorresponding to such touch input. The flexible touch screen may beconfigured to detect the touch input in the deformed state as well as inthe basic state.

The touch sensor detects the touch (or touch input) applied on the touchscreen using at least one of various touch schemes such as a resistivefilm scheme, a capacitance scheme, an infrared scheme, an ultrasonicwave scheme, a magnetic field scheme, and the like.

As an example, the touch sensor may be configured to convert a change inpressure applied on a specific portion of the touch screen, capacitancegenerated at the specific portion, or the like into an electrical inputsignal. The touch sensor may be configured such that a touch objectapplying a touch on the touch screen may detect touched position andarea on the touch sensor, a pressure during the touch, a capacitanceduring the touch, and the like.

Further, the mobile terminal 100 may have a deformation detection meansfor detecting the deformation of the flexible display unit 151. Suchdeformation detection means may be included in the sensing unit 140 (seeFIG. 1).

The deformation detection means may be disposed in the flexible displayunit 151 or a case (first to second frames 101 to 102 to be describedlater) to detect information related to the deformation of the flexibledisplay unit 151. In this connection, the information related to thedeformation may include a direction in which the flexible display unit151 is deformed, a degree of the deformation, a deformed position, adeformed time, an acceleration at which the deformed flexible displayunit 151 is restored, and the like. In addition, the information relatedto the deformation may include various kinds of information that may bedetected due to the bending of the flexible display unit 151.

In addition, the controller 180 may change information displayed on theflexible display unit 151 or generate a control signal for controlling afunction of the mobile terminal 100 based on the information related tothe deformation of the flexible display unit 151 detected by thedeformation detection means.

The deformation of the flexible display unit 151 may vary depending onthe positions of the first frame 101 and the second frame 102. As shownin FIG. 2, since the bending position on the flexible display unit 151is determined according to the positions of the first frame and thesecond frame, the bending deformation position of the flexible displayunit 151 and the area thereof positioned on the front may be calculatedbased on the positions of the first frame 101 and the first frame 102 inplace of the deformation detection means of the flexible display unit151.

The state conversion (first or second state) of the flexible displayunit 151, i.e., the size change at the front and rear faces of themobile terminal 100 of the display unit 151 based on the size change ofthe mobile terminal 100 may be performed manually by a force applied bythe user, but may be not limited to such manual scheme. For example,when the mobile terminal 100 or the flexible display unit 151 is in thefirst state, the mobile terminal 100 or the flexible display unit 151may be converted into the second state by the user or an applicationcommand without the external force applied by the user. As such, inorder for the flexible display unit 151 to be automatically deformedwithout the external force, the mobile terminal 100 may include adriving unit 200, which will be described later.

The flexible display unit 151 of the present disclosure is bent 180degrees by rolling around a side portion of the mobile terminal 100facing in the first direction. Accordingly, based on the side portion ofthe mobile terminal 100, a part of the flexible display unit 151 isdisposed on the front of the mobile terminal 100, and the other part ofthe flexible display unit 151 is disposed on the rear of the mobileterminal 100. For simplicity, the part of the flexible display unit 151positioned on the front is called a front face, and the other part ofthe flexible display unit 151 positioned on the rear is called a rearface. As illustrated in FIG. 2, the mobile terminal may extend in thefirst direction or contract in the second direction opposite to thefirst direction. In this case, the area of the flexible display unit 151positioned on the front changes. That is, the sizes of the front faceand the rear face may be changed according to a change in the state ofthe mobile terminal.

The part of the flexible display unit 151 positioned on the front of themobile terminal 100 may be immovably fixed to the front surface of thefirst frame 101, and the other part thereof positioned on the rear ofthe mobile terminal 100 may be movably arranged on the rear of themobile terminal 100.

In addition, the flexible display unit 151 may be rolled on or releasedat the side portion in the first direction of mobile terminal.Accordingly, the rear face of the display unit 151 moves, so that thesize of the front face of the display unit 151 may be adjusted. Sincethe size of the flexible display unit 151 is determined and the flexibledisplay unit 151 is formed of one continuous body, an area of rear faceof the display unit 151 decreases as an area of the front face of thedisplay unit 151 increases. Such a display unit 151 may be rolled in asecond frame 102, which is movable relative to a first frame 101 to bedescribed later, more correctly, on one of sides of the second frame102. The display unit 151 may be withdrawn or pulled out from orinserted or pushed into the second frame 102 while being rolled in thesecond frame 102 along a moving direction of the second frame 102 toadjust the area of the display unit 151 on the front face of the mobileterminal 100. Such operation will be described in more detail belowalong with other relevant components of the mobile terminal 100.

Typically, an antenna is disposed in the case or the housing of themobile terminal 100, but a portion where the antenna is installed in thecase or the housing may be limited because of the flexible display unit151 that covers not only the front face of the mobile terminal 100 butalso the rear face thereof. For this reason, the antenna may beimplemented on the flexible display unit 151. An antenna on display(AOD) is an antenna in which a transparent film is formed by stacking anelectrode layer and a dielectric layer that have patterns engravedthereon, respectively. The antenna on display may be implemented thinnerthan an antenna implemented using a laser direct structuring (LDS)technology using a conventional copper nickel plating scheme, so thatthe antenna on display may not be exposed to the outside withoutaffecting a thickness. In addition, the antenna on display may transmitand receive a signal directly to or from the display unit 151.Accordingly, the antenna on display may be used in the mobile terminal100 in which the display unit 151 is located on the both faces of themobile terminal 100 as in the present disclosure.

FIGS. 4 and 5 are exploded perspective views of the mobile terminal inaccordance with an embodiment. FIG. 4 is an exploded perspective view ofthe mobile terminal as viewed from the front side, and FIG. 5 is anexploded perspective view of the mobile terminal as viewed from the rearside.

The mobile terminal 100 of the present disclosure includes frames 101and 102 in which components are mounted, and the frames 101 and 102 ofthe present disclosure may vary in size in the first direction as shownin FIG. 2. One or more frames 101 and 102 move relative to each other,and sizes thereof may vary in the first direction. Electronic componentsare mounted in the frames 101 and 102, and the flexible display unit 151is located out of the frames 101 and 102.

Since the mobile terminal 100 of the present disclosure includes theflexible display unit 151, the flexible display unit 151 may be combinedin a form surrounding front faces and rear faces of the frames 101 and102. The frame may include the first frame 101 and the second frame 102moving in the first direction with respect to the first frame 101. Thefirst frame 101 and the second frame 102 include front portions, a rearportions, and side portions, respectively, and are coupled to eachother.

First, the first frame 101 corresponds to a main body of the mobileterminal 100, and may have a space between the first front portion 1011and the first rear portion 1012 therein for accommodating variouscomponents. In addition, the first frame 101 may accommodate the secondframe 102 movably coupled to the first frame 101 in such a space. Morespecifically, as shown in FIGS. 2 and 5, the first frame 101 may includea first front portion 1011 disposed at a front portion of the mobileterminal 100 and supporting the front face of the display unit 151 and afirst rear portion 1012 disposed at a rear portion of the mobileterminal and on which various components are mounted. A front deco 1016may cover front edges of the first area 151 a to protect the edges ofthe first area 151 a.

The first front portion 1011 and the first rear portion 1012 may bespaced apart from each other at a predetermined spacing to define apredetermined space therebetween, and may be connected to each other bya first side portion 1013. The first side portion 1013 may be integrallyformed with the first rear portion 1012 or the first front portion 1011.The camera 121, the audio output module 152, and the input/outputterminal, the controller 180, and the power supply unit 190 may beaccommodated as components of the mobile terminal 100 in the space inthe first frame 101. For example, the controller 180 may be a circuitboard 181 including a processor and an electronic circuit forcontrolling the operation of the mobile terminal, and the power supplyunit 190 may be a battery 191 and related components. In addition, thedriving unit 200 that controls the slide movement of the second frame102, which will be described later, may also be accommodated in thefirst frame 101.

As described above, the display unit 151 has the continuous body, andthus, may be disposed on both the front face and the rear face of themobile terminal 100 while being rolled in the mobile terminal 100. Thedisplay unit 151 may include the front face positioned at the front faceof the mobile terminal 100, the rear face positioned at the rear face ofthe mobile terminal 100, and the side face positioned between the frontface and the rear face thereof and surrounding the side face of themobile terminal. The front face and the rear face of the display unit151 are flat, and the side face of the display unit 151 may form acurved face. The flexible display unit 151 may be damaged when beingbent at an angle. Thus, the flexible display unit 151 may be formed tobe bent with a predetermined curvature at the side face.

The display unit 151 may be divided into a fixed portion 151 a and 151 band a variable portion 151 c. The fixed portion 151 a and 151 b means aportion fixed to the frame. Because of being fixed to the frame, thefixed portion 151 a and 151 b maintains a constant shape withoutchanging a bending degree. On the other hand, the variable portion 151 cmeans a portion in which a bending angle or a position of the bentportion changes. The variable portion 151 c in which the position orbending angle of the bent portion changes requires a structure forsupporting a rear face of the variable portion 151 c in response to thechange.

The fixed portion 151 a, 151 b is coupled to the first frame of thedisplay unit and is always positioned on the front face of the displayunit to form a portion of the front face of the display unit. Thevariable portion 151 c includes a side face located at a side portion ofthe mobile terminal, and a position of the side face varies depending onthe position of the second frame. Based on a side face, an area of aportion disposed on the front face of the display unit and an area of aportion disposed on the rear face of the display unit vary. That is, aportion of the variable portion 151 c may be the front face and anotherportion of the variable portion 151 c may be the rear face based on thefirst and second states. The variable portion 151 c is positioned in thefirst direction with respect to the fixed portion 151 a, 151 b relativeto the mobile terminal, and an end of the variable portion 151 c is benttoward the rear face of the mobile terminal and slides on the rear faceof the second frame.

The end of the variable portion of the display unit is coupled with aslide frame that guides the variable portion to slide move on the rearface of the second frame, and the slide frame moves in the firstdirection at the same time as the second frame moves in the firstdirection. As a result, a moving distance of the slide frame withrespect to the first frame is twice as a moving distance of the secondframe with respect to the first frame. Further, as shown in FIG. 3, thefirst rear portion 1012 of the mobile terminal 100 includes an exposedrear portion 1015 that is exposed to the outside without being coveredby the display unit 151 even in the first state. The physical input unit120 for the manipulation of the mobile terminal 100 such as variousbuttons, switches, the camera 121, and a flash, and the sensing unit 140such as the proximity sensor 141 or a fingerprint sensor may be arrangedon the exposed rear portion 1015. The first rear portion 1012 except forthe exposed rear portion 1015 may be covered by the display unit 151 inthe first state as shown in FIG. 3(a), and may be exposed rearward inthe second state as shown in FIG. 3(b).

In a conventional bar-shaped terminal, a display unit is provided onlyon a front face of the terminal. Therefore, a main camera is placed on arear face of the terminal in order for the user to capture an object atan opposite side while looking through the display unit. On the otherhand, an additional auxiliary camera is required to be disposed on thefront face of the terminal in order for the user to capture himself orherself while viewing himself or herself through the display unit.

In the mobile terminal 100 of the present disclosure, on the other hand,the display unit 151 is arranged on both the front and rear of themobile terminal 100. Accordingly, when a user photographs himself, aportion of the display unit 151 positioned on the same surface as thecamera 121, that is, the rear face of the display unit 151 may be used.When the user takes a photograph of an object around the user, a portionof the display unit 151 on the side facing away from the camera 121,that is, the front face of the display unit 151 may be used. For thisreason, the mobile terminal 100 may take a photograph of the user or anobject located around the user using one camera 121. The camera mayinclude a plurality of cameras having different angles of view, such aswide angle, ultra wide angle, and telephoto angle. Not only the camerabut also a proximity sensor and an audio output unit may be disposed onthe exposed rear portion 1015, and an antenna may be installed on therear portion 1015. The rear portion 1015 may be used to protect thecamera, the sensor, or the like on the exposed rear portion 1015 and notto deteriorate the exterior design. A portion of the rear portion 1015corresponding to the camera 121 or the sensor 140 may be configured tobe transparent, and the other portion thereof may have a predeterminedpattern or color in consideration of design aspects without exposinginternal parts.

The first side portion 1013 may extend along the edges of the firstfront portion 1011 and the first rear portion 1012 to surround thecircumference of the first frame 101 and may define the appearance ofthe mobile terminal 100. However, as mentioned above, the second frame102 is accommodated in and movably coupled to the first frame 101, andtherefore a portion of the first frame 101 needs to be open to allowmovement of the second frame 102 relative to the first frame 101. As anexample, as best shown in FIG. 2, the second frame 102 may be movablycoupled to a side of the first frame 101 facing in the first direction,and accordingly the first side portion 1013 may not be formed on thelateral surface facing in the first direction such that the lateralsurface is open. Since the first side portion 1013 is exposed to theoutside of the mobile terminal 100, the interface unit 160 forconnecting a power port or an ear jack or the user input unit 120, suchas a volume control button, may be disposed on the first side portion1013. When the first side portion 1013 contains a metal material, thefirst side portion 1013 may serve as an antenna.

The second frame 102 may include a second front portion 1021 disposed atthe front portion of the mobile terminal 100 and a second rear portion1022 disposed at the rear portion of the mobile terminal 100. Like thefirst front portion 1011 and the first rear portion 1012 of the firstframe 101, the second front portion 1021 and the second rear portion1022 may be formed of plate-shaped members that are generally flat. Inaddition, the second frame 102 also accommodates various components, andmust not interfere with the components accommodated in the first frame101 during the movement. Accordingly, the second front portion 1021 andthe second rear portion 1022 may be coupled to each other in a state ofbeing spaced apart from each other to define a predetermined spacetherebetween, and may have shapes that do not interfere with thecomponents in the first frame 101.

FIG. 6 is a side view of the mobile terminal as viewed from a thirddirection. FIG. 6 shows the first side portion 1013 of the first frame101 and a second side portion 1023 of the second frame 102. Since theflexible display unit 151 is positioned at an end of the second frame102 facing in the first direction, the end of the second frame 102facing in the first direction should not be exposed to the outside. Anend of the second frame 102 facing in the second direction should beopen so as not to interfere with the first frame 101. In the firststate, the second side portion 1023 of the second frame 102, which ispositioned on the side facing in the third direction (which refers tothe upward or downward direction in the drawing or may include both theupward and downward directions), may not be exposed to the outsidebecause it overlaps the first side portion 1013 of the first frame.However, in the second state, it may be exposed to the outside becausethe second frame 102 is drawn out.

In addition, the display unit 151 may be bent 180 degrees while beingrolled in the second frame 102 to be disposed on both the front face andthe rear face of the mobile terminal 100. For such an arrangement of thedisplay unit 151, the second frame 102 may include a roller 210rotatably disposed therein. The roller 210 may be disposed at anyposition inside the second frame 102. However, the display unit 151should be spread flat on the front face and the rear face of the mobileterminal 100 to provide a good quality screen to the user. Further, forsuch spread, a proper tension must be provided on the display unit 151.In order to provide the proper tension, the roller 210 may be disposedat a first directional end of the second frame 102. The roller 210 mayextend in the third direction, and may be rotatably coupled to thesecond frame 102.

The display unit 151 may be rolled around the roller 210 while beinggently bent with a predetermined curvature. The flexible display unit151 may include a first face on which a video is output and exposed tothe outside and an inner face facing the frame at the opposite side. Theroller 210 may be installed to rotate freely in the second frame 102while being in contact with the inner face of the display unit 151.Accordingly, the roller 210 may actually move the display unit 151 in alateral direction of the mobile terminal 100, that is, in a directionperpendicular to a longitudinal direction. As will be described later,when the second frame 102 slides, because of the tension applied by thesecond frame 102, the display unit 151 moves to the front face or therear face of the mobile terminal 100 in different directions (i.e., thefirst direction D1 or the second direction D2) relative to the secondframe 102. The roller 210 may guide such movement while rotating.

The roller 210 may be disposed adjacent to the end of the second frame102 that faces in the first direction. A side frame 1024 may be disposedat the end of the second frame 102 facing in the first direction toprevent damage to the display unit 151 rolled around the roller 210.

The side frame 1024 may extend in the longitudinal direction (the thirddirection) of the second frame 102 to cover the side portion facing inthe first direction, thereby protecting the roller 210 and the displayunit 151 rolled therearound.

The side frame 1024 may substantially define the appearance of themobile terminal 100 in cooperation with the first side portion 1013 ofthe first frame 101. In addition, the side portion of the second frame102 that faces in the second direction may be omitted to minimizeinterference with the components arranged in the first frame 101 duringmovement.

During the expansion and the contraction in such first and seconddirections D1 and D2, the second frame 102 may overlap the first frame101, more precisely, the first front portion 1011 and the first rearportion 1012 thereof so as not to interfere with the first frame 101.More specifically, the display unit 151 may be coupled to and supportedby the first front portion 1011 of the first frame 101, as describedabove. Accordingly, the display unit 151 does not need to beadditionally supported by the second front portion 1021 of the secondframe 102. Rather, when the second front portion 1021 is interposedbetween the first front portion 1011 and the display unit 151, thedisplay unit 151 may be deformed or damaged because of friction with thesecond front portion 1021, which is repeatedly moved. Thus, the secondfront portion 1021 may be disposed below the first front portion 1011,or may be interposed between two first front portions 1011. The secondrear portion 1022 of the second frame 102 may be disposed rearward ofthe first rear portion 1012 of the first frame 101. That is, the frontface of the second rear portion 1022 may face the rear face of the firstrear portion 1012. In addition, the rear face of the first rear portion1012 may be in contact with the front face of the second rear portion1022 to stably support the movement of the second frame 102. Because ofsuch arrangement, the second rear portion 1022 may be exposed to theoutside of the first frame, more precisely, of the first rear portion1012, and may be coupled to the display unit 151.

In addition, the second frame 102 may extend and contract in the firstand second directions D1 and D2 to change the size of the mobileterminal 100, particularly, to extend or contract the front face of themobile terminal 100. Thus, the display unit 151 must move by suchextended or reduced front face size to obtain the intended first andsecond states. However, when being fixed to the second frame 102, thedisplay unit 151 may not be moved smoothly to be adapted for the frontface of the mobile terminal 100 that is extended or contracted. For thisreason, the display unit 151 may be movably coupled to the second frame102.

More specifically, the display unit 151 may include a first region 151 adisposed on the front of the mobile terminal 100, a second region 151 bcoupled to a slide frame 103 positioned on the rear of the mobileterminal 100, and a third region 151 c located between the first region151 a and the second region 151 b and bent around the roller 210. Thethird region 151 c may move to the front or the rear according to changein the state of the mobile terminal 100. The slide frame 103 may beformed of a plate-shaped member extending in the longitudinal direction(the third direction) of the mobile terminal 100, and may be coupled tothe second rear portion 1022 so as to be movable in the first and seconddirections D1 and D2.

The first to third regions 151 a, 151 b, and 151 c may be connected toeach other, and may form a continuous body of the display unit 151. Inaddition, as described above, for the movement of the third region 151 ctoward the front face or the rear face of the mobile terminal 100depending on the moving direction of the second frame 102, the firstregion 151 a may be fixed so as not to move to the front face of themobile terminal 100, and the second region 151 b may be provided to bemovable on the rear face of the mobile terminal. Such configuration ofthe display unit 151 will be described in more detail below.

The first region 151 a may be disposed on the front face of the mobileterminal 100, more specifically, the first frame 101, that is, on thefront face of the first front portion 1011. The first region 151 a isfixed to the first frame 101, that is, the front face of the first frontportion 1011 so as not to be moved during the movement of the secondframe 102, and thus, the first region 151 a may always be exposed to thefront face of the mobile terminal 100.

The third region 151 c may be adjacent to the first region 151 a in thefirst direction and rolled on the roller 210. The third region 151 c maypartially cover the second frame 102, that is, the rear face of thesecond rear portion 1022. Further, the second frame 102, that is, thesecond rear portion 1022, is adjacent to the first frame 101, that is,the first rear portion 1012 and together forms the rear case of themobile terminal 100. Accordingly, it may be described that the thirdregion 151 c is also disposed on the rear face of the first frame 101.

The second region 151 b may be adjacent to the third region 151 c andmay be disposed on the rear face of the mobile terminal 100, morespecifically, on the second frame 102, that is, the rear face of thesecond rear portion 1022 thereof. The second region 151 b may be coupledto the slide frame 103 without being directly coupled to the secondframe 102.

As a result, the first region 151 a may be disposed on the front face ofthe mobile terminal 100 and may be always exposed to the front faceregardless of the movement of the second frame 102, and the secondregion 151 b may be disposed on the rear face of the mobile terminal 100and may be always exposed to the rear face regardless of the movement ofthe second frame 102. In addition, the third region 151 c may bedisposed between the first and second regions 151 a and 151 b, and maybe selectively placed on the front face or the rear face of the mobileterminal 100 depending on the moving directions D1 and D2 of the secondframe 102.

Because of such selective placement of the third region 151 c, the firstrear portion 1012 of the first frame 101 may be exposed to the outsideof the mobile terminal 100 because the first rear portion 1012 iscovered by the second and third regions 151 b and 151 c and the secondrear portion 1022 of the display unit 151 in the first state, but, inthe second state, the third region 151 c moves to the front face of themobile terminal 100 and the second rear portion 1022 also moves in thefirst direction D1. In addition, the second front portion 1021 of thesecond frame 102 is hidden by the first front portion 1011 of the firstframe 101 in the first state, but, in the second state, moves out of thefirst frame 101 to support the third region 151 c of the display unit151 disposed on the front face of the mobile terminal 100.

In order to prevent the second front portion 1021 from affecting theinternal components during the slide movement, a separating plate 1017may be further disposed rearward of the second front portion 1021 andfastened with the first front portion 1011. The second front portion1021 may move between the first front portion 1011 and the separatingplate 1017 based on the slide movement of the second frame.

However, the third region 151 c may be rolled on the roller 210 and bentin the second frame 102. When converting from the first state to thesecond state, the third region 151 c may extend from the second frame102 to the front face of the mobile terminal 100 while being rolled onthe roller 210 in one direction. On the other hand, when converting fromthe second state to the first state, the third region 151 c may beretracted from the front face of the mobile terminal 100 to the secondframe 102 while being rolled on the roller 210 in the oppositedirection, and at the same time, may return to the rear face of themobile terminal 100 from the second frame 102.

A specific location of the foldable mobile terminal in a form of beingspread like a book is easily damaged because only the specific locationis folded repeatedly. On the other hand, the deformed portion of theflexible display unit 151, that is, a portion rolled on the roller 210,may vary based on the first and second states of the mobile terminal100, that is, the movement of the second frame 102. Accordingly, themobile terminal 100 of the present disclosure may significantly reducedeformation and fatigue repeatedly applied to a specific portion of thedisplay unit 151, thereby preventing damage to the display unit 151.

Based on the above-described configuration, overall operations of themobile terminal 100 will be described as follows. As an example, thestate conversion may be performed manually by the user, and an operationof the mobile terminal 100 during such manual state conversion will bedescribed. However, operations of the first to third frames 101 to 103and the display unit 151, which will be described below, may beperformed in the same manner when a power source other than a user'sforce is used, for example, when the driving unit 200 to be describedbelow is applied.

A rear face cover 1025 may be further disposed on a rear face of thesecond rear portion 1022 such that the rear face of the display unitpositioned on the rear face of the mobile terminal 100 is not exposed tothe outside. The rear face of the display unit may be used in the firststate when the rear face cover 1025 uses a transparent material, and therear face of the display unit may be covered such that the movement ofthe slide frame 103 is not exposed when the rear face cover 1025 uses anopaque material. That is, the second region and the third region of theslide frame 103 and the display unit 151 may move in the first directionand in the second direction in a space between the second rear portion1022 and the rear face cover 1025.

FIG. 7 is a view showing a driving unit 200 of the mobile terminal 100in accordance with an embodiment. FIG. 7(a) shows the first state andFIG. 7(b) shows the second state. The mobile terminal 100 of the presentdisclosure may be switched between the states in a manner in which auser manually pulls the second frame 102 in the first direction D1 orpushes the same in the second direction D2 with respect to the firstframe 101. However, in the manual method, applying excessive force tothe body of the mobile terminal 100 may damage the mobile terminal 100.Accordingly, a driving unit 200 employing a motor 201 may be furtherprovided to cause the second frame 102 to stably move withoutdistortion.

As the motor 201, a motor 201 configured to provide rotational force asshown in FIG. 7, or a linear motor 201 configured to make linear motionmay be used. The motor 201 configured to provide the rotational forceshould have a large diameter to provide large force. Two motors 201 maybe used as shown in FIG. 7 to provide driving force of a predeterminedmagnitude or more in the limited space of the mobile terminal 100without increasing the thickness.

If the second frame 102 is moved excessively fast, damage or malfunctionmay occur. Accordingly, a planetary gear configured to decrease thespeed of the motor 201 to ensure movement at a stable speed may befurther provided. The planetary gear 202 serves to amplify or attenuatethe number of revolutions of the motor 201 using a plurality of discgears having different numbers of teeth. The motor 201 may be fixed tothe first frame 101 as shown in FIG. 7(a). The position of the motor 201is fixed even when the second frame 102 moves in the first direction toswitch the mobile terminal 100 to the second state, as shown in FIG.7(b).

Since the second frame 102 linearly moves with respect to the firstframe 101 in the first direction or the second direction, rack andpinion gears configured to convert the rotational force of the motor 201into linear motion may be used. A pinion gear to receive the rotationalforce of the motor 201 may be arranged to engage with a rack gear 205composed of teeth continuously arranged in the first direction. Thepinion gear may be fixed to the first frame 101 together with the motor201 and the rack gear 205 may be positioned on the second frame 102.Alternatively, the rack gear 205 may be positioned on the first frame101, and the motor 201 and the pinion gear may be arranged on the secondframe 102. Since the motor 201 holds the pinion gear such that thepinion gear does not rotate, the second frame 102 may maintain the firststate and the second state. However, when large external force isapplied, the second frame 102 may be displaced as the pinion gearrotates.

A stopper (not shown) configured to fix the positions of the secondframe 102 or the rack gear 205 and the first frame 101 may be furtherprovided to fix the mobile terminal 100 in the first state or the secondstate. When electric current flows through the motor 201 to drive themotor 201, the stopper may be released to allow the movement of thesecond frame 102. When power is not applied to the motor 201 and thusthe motor 201 does not rotate, the first frame 101 and the second frame102 may be fastened such that the positions thereof are fixed.

When a pair of driving units 200 is symmetrically disposed in thevertical direction (the third direction), stable movement may be made.However, to arrange a battery or the like, the driving unit 200 shouldbe arranged biased to one side in consideration of the limited mountingspace of the mobile terminal 100 as shown in FIG. 7(a). According tosuch asymmetric arrangement of the driving unit 200, the second frame102 may be distorted during movement due to a difference in movementspeed between the upper end portion and the lower end portion. Toaddress this issue, a linear guide 230 may be further provided.

The linear guide 230 may be disposed at both ends of the mobile terminal100 facing in the third direction, that is, on the upper and lower sidesof the mobile terminal 100, in order to supplement the function of onedriving unit 200 biased to one side in the third direction. The linearguide 230 may include a guide rail 231 extending in the first directionand a guide block 232 configured to move along the guide rail 231. Theguide rail 231 may be disposed on the first frame 101 and the guideblock 232 may be disposed on the second frame 102, or vice versa. Inthis embodiment, the guide rail 231 may be disposed on the second frame102 to cover the upper and lower sides of the extended portion of thesecond frame 102 in the second state.

After the guide block 232 is coupled to the first frame 101 and theguide rail 231 is coupled to the second frame 102, the guide block 232and the guide rail 231 may be slidably fastened to each other. However,for convenience of the fastening, the guide block 232 and the guide rail231 fastened to each other. Then, the guide block 232 may be first fixedto the first frame 101, and then the second frame 102 may be coupled tothe guide rail 231.

The guide block 232 may be provided with a guide groove into which theguide rail 231 is inserted. Alternatively, the guide rail 231 may beprovided with a rail groove into which a portion of the guide block 232is inserted. The fastening portions of the guide rail 231 and the guideblock 232 may be formed to be bumpy. Accordingly, movement in the firstdirection or the second direction may be made without displacement inthe thickness direction of the mobile terminal 100. In order to reducefriction between the guide block 232 and the guide rail 231, aself-lubricating member having high wear resistance and low frictionresistance, such as a bearing or polyoxymethylene (POM), may be added tothe inside of the guide groove.

FIG. 8 is a cross-sectional view taken along lines A-A and B-B in FIG.2. As illustrated in FIG. 2, when the second frame 102 switches to thesecond state by moving in the first direction, the third region 151 cpositioned on the rear side moves to the front, and thus a structure tosupport the rear surface of the third region 151 c moved to the front isrequired. The second front portion 1021 positioned on the front surfaceof the second frame 102 may be positioned on the rear surface of thethird region 151 c in the second state. However, in the first state, thesecond front portion 1021 is disposed to overlap the first front portion1011 of the first frame 101, and accordingly the first front portion1011 and the second front portion 1021 form a step. A boundary is formedbetween the first region 151 a and the third region 151 c of theflexible display unit 151 by the step formed by the first front portion1011 and the second front portion 1021. A rolling plate 104 may be usedas a support structure to fill the gap between the second front portion1021 and the third region 151 c of the flexible display unit 151.

The rolling plate 104 may be positioned on the rear surface of theflexible display unit 151, and have a thickness corresponding to the gapbetween the second front portion 1021 and the flexible display unit 151in the second state. As shown in FIG. 8(a), in the first state, therolling plate 104 is rolled around the roller 210 and is positioned onthe lateral side and rear side of the mobile terminal 100. The flexibledisplay unit 151 and the rolling plate 104 may be positioned between thesecond rear portion of the second frame 102 and a rear cover 1025provided to cover the rear face of the display unit 151. As shown inFIG. 8(b), when switch to the second state occurs, the rolling plate 104may move to the front and the rolling plate 104 may be positioned on thefront portion of the second frame 102.

The third region 151 c of the display unit 151 in which the rollingplate 104 is positioned is a portion where bending deformation occurswhen switch from the first state to the second state occurs.Accordingly, the rolling plate 104 may be deformed according todeformation of the third region 151 c. Here, the rolling plate 104 isrequired to have a predetermined stiffness to maintain the flat statewhen the flexible display unit 151 is positioned on the front or rear ofthe mobile terminal. That is, the rolling plate 104 needs a structurecapable of maintaining the flat state in the third direction andperforming bending deformation in the first direction.

FIG. 9 is a view illustrating a display unit 151 and a rolling plate 104of the mobile terminal 100 in accordance with an embodiment. The rollingplate 104 may include multiple support bars 1041 extending in the thirddirection. The multiple support bars 1041 may be arranged side by sidein the first direction and spaced apart from each other by apredetermined distance. Accordingly, even when the flexible display unit151 is rolled around the roller 210 and is thus bent, interferencebetween the support bars 1041 may be avoided. The support bars 1041 maybe implemented with an injection molding material having a predeterminedthickness for stiffness, and may include materials such as SUS orferrosilicon (FeSi).

The multiple support bars 1041 may be directly attached to the rearsurface of the display unit 151. However, this operation may take a longtime and produce a lot of defects, resulting in poor productivity. Inaddition, directly processing the display unit 151 is highly likely todamage the display unit 151. Therefore, a rolling sheet 1045 to fix themultiple support bars 1041 may be further provided. The rolling sheet1045 may include a metal material, and may employ a superelasticmaterial that is bending-deformable and capable of recovering the flatstate after the bending deformation. For example, a superelastic metalsheet such as a thin STS sheet of 0.05 mm or less may be used. Anadhesive tape may be attached to both surfaces of the rolling sheet 1045to bond the rolling sheet 1045 to the support bars 1041 and bond therear surface of the display unit 151 to the rolling sheet 1045.

The rolling sheet 1045 may be provided with a kerf pattern in whichmultiple grooves extending in the third direction are formed in thefirst direction. The grooves in the kerf pattern may be formed betweenthe multiple support bars 1041. The grooves may be formed on a surfaceof the rolling sheet 1045 to which the support bars 1041 are bonded. Thekerf pattern may be formed in a wedge shape that is formed by beinggradually narrowed from the surface portion of the rolling sheet 1045.

Instead of the rolling sheet 1045, an elastic material such as siliconemay be disposed between the support bars 1041 to join neighboringsupport bars 1041. In this case, the angle between the support bars 1041may be varied. The elastic connector may be bent at a positioncorresponding to the roller 210. When positioned on the front or rear ofthe mobile terminal, the elastic connector may be unfolded such that thesupport bars 1041 are disposed forming a flat surface.

The support bars 1041 may form a flat surface corresponding to the rearsurface of the display unit 151. Alternatively, as shown in FIG. 8(b),the support bars 1041 may be formed in a shape having a predeterminedcurvature. The curved support bars 1041 may closely contact the curvedsurface of the roller 210 when the rolling plate 104 is rolled aroundthe roller 210. Alternatively, one surface of the support bars 1041 incontact with the display unit 151 maintains a flat state, and the othersurface thereof on the opposite side may include a curved surfacecorresponding to the curvature of the roller 210. In this case, thesupport bars 1041 may be thick at the ends thereof facing in the firstand second directions and have the thinnest portion in the middlethereof.

The rolling plate 104 may be disposed at a position corresponding to thethird region 151 c and is rolled and bent around the roller 210. Thus,the rolling plate 104 may span over the front and rear surfaces. Therolling plate 104 is connected to the first front portion 1011 of thefirst frame 101 on the front side and connected to the slide frame 103on the rear side. In order for the flexible display unit 151 to form acontinuous surface without a step, the first front portion 1011 of thefirst frame 101 positioned on the rear surface of the first region 151a, the slide frame 103 positioned on the rear surface of the secondregion 151 b, and the rolling plate 104 positioned on the rear surfaceof the third region 151 c may be arranged such that the surfaces thereofin contact with the display unit 151 are at the same height. Inparticular, since the slide frame 103 moves on the rear of the mobileterminal 100 and moves in the same space as the rolling plate 104, therolling plate 104 may have a thickness corresponding to the thickness ofthe slide frame 103.

FIG. 10 is a view illustrating an issue raised in an extendable mobileterminal 100. The figure shows the end of the second frame 102 in thethird direction when the second frame 102 is extended as switching fromthe first state to the second state occurs. Since the display unit 151contains a flexible material, the display unit 151 may be bent at aposition corresponding to the roller 210. However, when the display unit151 is positioned on the front of the mobile terminal 100 in the secondstate, it should be maintained in a flat state. Since the rolling plate104 is not fixed to the second frame 102, the display unit 151 may sagdownward as shown in FIG. 10(a) or rise upward as shown in FIG. 10(b).

The sagging issue of the display unit 151 (in FIG. 10(a)) may beaddressed when the support bars 1041 of the rolling plate 104 describedabove support the rear surface of the third region 151 c of the displayunit 151 and the front portion of the second frame 102 supports thesupport bars 1041. However, in order to address an issue that thedisplay unit 151 moved to the front is not arranged flat but isseparated from the second frame 102 as shown in FIG. 10(b), the rollingplate 104 and the second frame 102 may further include a slide structure1043, 1027. The slide structures 1043 and 1027 may fasten the rollingplate 104 (the display unit 151) so as not to be separated from thesecond frame 102 in the thickness direction of the mobile terminal 100while allowing the movement thereof only in the first direction or thesecond direction.

FIGS. 11 to 13 are views showing the slide structures 1043 and 1027provided on the rolling plate 104 and the second frame 102. FIG. 11 is across-sectional view taken along lines C-C and D-D in FIG. 2, FIG. 12 isa cross-sectional view taken along lines E-E and F-F in FIG. 11, andFIG. 13 is a view showing an expanded side portion 1042 and a guide hook1043 of the mobile terminal 100 in accordance with an embodiment.

As shown in FIG. 13, the rolling plate 104 may include a slide hook 1043protruding toward the second side portion 1023 positioned on the side ofthe second frame 102 facing in the third direction. As shown in FIG. 11,the second side portion 1023 of the second frame 102 may include a sliderail 1027 into which the slide hook 1043 is movably inserted. FIG. 11shows the slide rail 1027 formed on the second side portion 1023 of thesecond frame 102. The slide rail 1027 may include a pair of horizontalportions 1027 a and 1027 b arranged side by side in a thicknessdirection and a curved portion 1027 c connecting ends of the horizontalportions 1027 a and 1027 b facing in the first direction. The pair ofhorizontal portions 1027 a and 1027 b and the curved portion 1027 c mayform a U shape, and the slide hook 1043 may move along the slide rail1027.

In the first state, the slide hook 1043 may be positioned in thehorizontal portion 1027 a, 1027 b positioned on the rear side, as shownin FIG. 11(a). In the second state, the slide hook 1043 may be moved tothe horizontal portion 1027 a, 1027 b positioned on the front side, asshown in FIG. 11(b). When moved from the rear horizontal portion 1027 ato the front horizontal portion 1027 b, the slide hook 1043 may passthrough the curved portion 1027 c. When the slide hooks 1043 passthrough the curved portion 1027 c, the rolling plate 104 may be bent andthe space between the slide hooks 1043 may be narrowed.

The slide rail 1027 along which the slide hook 1043 moves may guide themovement of the slide hook 1043 and the movement of the slide frame 103simultaneously. Since the slide frame 103 is also disposed adjacent tothe support bars, a slide hook 1033 protruding from the slide frame 103may be further provided.

FIG. 12(a) shows the second frame 102 in the first state in which thefirst frame 101 and the second frame 102 overlap each other, and FIG.12(b) shows the second frame 102 moved from the first frame 101 in thefirst direction in the second state. As shown in FIG. 12(a), the supportbars 1041 and the slide hooks 1043 are positioned on the rear in thefirst state. In the second state, as shown in FIG. 12(b), the supportbars 1041 and the slide hooks 1043 are positioned on the front. Thedistance from the front face of the display unit 151 to the fronthorizontal portions 1027 a and 1027 b may be equal to the distance fromthe rear face of the display unit 151 to the rear horizontal portions1027 a and 1027 b.

When large friction occurs during movement of the slide hooks 1043 alongthe slide rail 1027, a large load may be applied to the driving unit200, thereby generating frictional noise or affecting the durability ofthe product. A self-lubricating member having high abrasion resistanceand low friction resistance, such as polyoxymethylene (POM), may be usedto facilitate the movement of the slide hooks 1043 on the slide rail1027. By forming the slide hooks 1043 in a cylindrical shape, the areathereof in contact with the slide rail 1027 may be minimized.

As illustrated in FIG. 13, a slide roller 1044 fitted onto the slidehook 1043 may be further provided. The slide roller 1044 may be fittedonto the cylindrical slide hook 1043 to rotate about an axis extendingin a direction in which the slide hook 1043 protrudes. The slide roller1044 may rotate when the slide hook 1043 moves along the slide rail1027, thereby reducing friction generated between the slide roller 1044and the slide rail 1027.

A bearing structure may help to reduce the friction, but it may increasethe overall size. For this reason, a simple ring-shaped slide roller1044 may be used. A fastening groove 1043 a and a fastening protrusion1044 a may be further provided to prevent the slide roller 1044 frombeing separated from the slide hook 1043. When the fastening protrusion1044 a is inserted into the fastening groove 1043 a, the fasteninggroove 1043 a formed on the outer circumferential surface of the slidehook 1043 in a ring shape and the ring-shaped fastening protrusion 1044a protruding from the inner surface of the slide roller 1044 arefastened to each other.

The second side portion 1023 of the second frame 102 is disposedoverlapping the first side portion 1013 of the first frame 101 in thefirst state, and is exposed to the outside in the second state. Sincethe second side portion 1023 is positioned inside the first side portion1013 of the first frame 101 in the first state, it may be difficult toconnect the interface unit 160, the user input unit 123, the audiooutput unit 152, the antenna, and the like, which are positioned on thefirst side portion 1013, to the printed circuit board 181, which ispositioned inside.

The second side portion 1023 may include an opening 1023 a formed byomitting at least a part of the second side portion 1023 to connect thecomponents positioned on the first side portion 1013 to the printedcircuit board 181 positioned inside the first frame 101. Through theopening 1023 a, a connector may be arranged between the componentspositioned on the first side portion 1013 and the printed circuit board.The opening 1023 a may have a shape elongated in the first direction toprevent interference between the connector and the second side portion1023 of the second frame 102 even when the second frame 102 is moved.

However, in order to prevent the inside of the mobile terminal 100 frombeing exposed through the opening 1023 a in the second state, anexpanded side portion 1042 may be formed at an end of the support bar1041 to cover the opening 1023 a in the second state. The expanded sideportion 1042 may have a larger area than the cross section of thesupport bar 1041 at the end of the support bar 1041. The slide hook 1043may be formed on a first expanded side portion 1042 a extending in adirection away from the display unit 151. When the slide hook 1043 isdisposed parallel to the support bar 1041, the second side portion 1023of the second frame 102 should be extended adjacent to the display unit151, which may make it difficult to form the opening 1023 a.Accordingly, the slide hooks 1043 may be formed at positions spacedapart from the display unit 151 by a predetermined distance. The firstexpanded side portion 1042 a may be formed in a fan shape to have awidth that is reduced as the first expanded side portion 1042 a extendsin a direction away from the display unit 151. FIG. 13 is a view showingan embodiment of the rolling plate 104 of the mobile terminal 100. Sincethe rolling plates at positions on the curved portion 1027 c of theslide rail 1027 spaced apart from the display portion 151 are disposedadjacent to each other, the first expanded side portion 1042 a may beformed in a fan shape to prevent the rolling plates from overlappingeach other.

The expanded side portion 1042 may also extend in the left-rightdirection, and may thus cover a space between neighboring support bars1041. The expanded side portion 1042 may further include a secondexpanded side portion 1042 b forming a step with respect to the firstexpanded side portion 1042 a as shown in FIG. 13. The second extensionside portion 1042 b may be disposed to overlap the first expanded sideportion 1042 a adjacent thereto to cover the space between the supportbars 1041. The second expanded side portion 1042 b may have a sizecorresponding to the thickness-wise size of the opening 1023 a formed inthe second side portion 1023 of the second frame 102. The secondexpanded side portion 1042 b may be formed to be shorter than the firstexpanded side portion 1042 a on the side spaced apart from the displayunit 151. The second expanded side portion 1042 b may be formed to beshorter than the first expanded side portion 1042 a to prevent thesecond expanded side portions 1042 b from overlapping each other whenthe rolling plates pass through the curved portion 1027 c of the sliderail 1027. The second expanded side portion 1042 b may be formed to havea size corresponding to the size of the opening 1023 a to cover thespace between the first expanded side portions 1042 a to prevent theinside of the second frame 102 from being exposed to the outside.

As shown in FIG. 14, the second expanded side portion 1042 b may haveany shape as long as the shape ensures that the second expanded sideportions 1042 b do not interfere with each other, and allows the secondexpanded side portion 1042 b to cover the space between the firstexpanded side portions 1042 a and to cover the opening 1023 a of thesecond side portion 1023 of the frame 102. It may have a rectangularshape as shown in FIG. 14(a) or a semicircular shape as shown in FIG.14(b).

FIG. 15 is a view illustrating another embodiment of the mobile terminal100 and an expanded side portion 1042 of the rolling plate 104. In themobile terminal 100 of this embodiment, the first frame 101 and thesecond frame 102 are arranged in a vertical direction, and therefore thefirst direction becomes a lower direction in the drawing.

Although the length of the first direction where the first frame 102 andthe second frame 102 are expanded is shorter than the length of thethird direction vertical to the first direction in the aforementionedembodiment, the length of the first direction of the first frame 101 andthe second frame 102 is longer than that of the third direction in thisembodiment.

Although there is a difference in arrangement directions and sizes ofthe frames 101, 102 and 103, when the second frame 102 moves in thefirst direction as described in the aforementioned embodiment, an areaof a front surface of the display unit 151 may be expanded and the slideframe 103 may also move in the first direction.

As the second frame 102 and the slide frame 103 move in the firstdirection, the mobile terminal 100 is switched from the first state tothe second state. On the other hand, as the second frame 102 and theslide frame 103 move in the second direction, the mobile terminal 100 isswitched from the second state to the first state. This principle is thesame as the aforementioned embodiment.

However, since the length of the first direction is longer than that ofthe third direction, the length of the support bar 1041 of the rollingplate 104 may be shorter than that of the aforementioned embodiment andthe number of the support bars 1041 may be more than that of theaforementioned embodiment.

As illustrated in FIG. 16(b), in the same manner as the aforementionedrolling plate 104, the expanded side portion 1042 formed at the endportion of the support bar 1041 has a shape that gradually becomesnarrow in the thickness direction of the mobile terminal 100, whereinthe slide hook 1043 is protruded at a narrow portion, and the supportbar 1041 is arranged at a wide portion.

In order that the display unit 151 is bent to form a smooth curve, thedisplay unit 151 coupled to the support bar 1041 should become a neutralplane and a support structure that includes the rolling plate 104coupled to a rear surface (which means an opposite surface of an exposedsurface) of the display unit 151 should be downsized at a curved portionwhere the display unit 151 is curved by being rolled in the roller 210.

FIG. 16 is a view illustrating a problem of the rolling plate 104 of themobile terminal 100. When the rolling plate 104 slidably moves on a flatsurface, the support bar 1041 should move at the same angle as that ofits adjacent support bar 1041 to maintain the flat surface.

However, as illustrated in FIG. 16(a), if the slide hook 1043 is caughton the slid rail or an interval between the plurality of slid hooks 1043is changed, the angle of the support bar 1041 is twisted. As illustratedin FIG. 16(b), a problem occurs in that bending is formed in the displayunit 151 coupled to the support bar 1041.

Also, as the support bar 1041 is twisted, the display unit 151 shouldbecome a neutral plane but a tensile force or contractile force may beapplied thereto, whereby the display unit 151 may be damaged.

A guide portion for preventing bending from occurring in the display 151by preventing the angle of the support bar 1041 and the expanded sideportion 1042 from being randomly changed as illustrated in FIG. 16(a) isrequired.

FIGS. 17 to 19 are views illustrating the expanded side portion 1042that includes guide bumps 10426 and 10427 to solve the above problem.The expanded side portion 1042 of this embodiment includes guide bumps10426 and 10427 protruded and inserted to overlap its adjacent expandedside portion 1042 by being engaged with its adjacent expanded sideportion 1042. The guide bumps guide the support bar 1041 and theexpanded side portion 1042 to move within only a limited angle range.

The expanded side portion 1042 includes a guide protrusion 10426protruded toward its adjacent expanded side portion 1042 and a guidegroove 10427 inserted to an opposite side of the guide protrusion 10426in a shape corresponding to the guide protrusion 10426, wherein theguide protrusion 10426 of the adjacent expanded side portion 1042 isinserted into the guide groove 10427. The guide groove 10427 and theguide protrusion 10426 are alternately arranged, and the plurality ofexpanded side portions 1042 are arranged to overlap each other.

The guide protrusion 10426 includes a first contact surface 10421 thatadjoins the guide groove 10427 of the expanded side portion 1042adjacent thereto, and the guide groove 10427 includes a second contactsurface 10422 that adjoins the first contact surface 10421. The firstcontact surface 10421 and the second contact surface 10422 may transfera force to the first direction when the second frame 102 moves in thefirst direction or the second direction (x axis direction of FIG. 19).

The guide protrusion 10426 and the guide groove 10427 may include athird contact surface 10423 and a fourth contact surface 10424 inaddition to the first contact surface 10421 and the second contactsurface 10422. The third contact surface 10423 and the fourth contactsurface 10424 may restrict movement of a thickness direction of a unitrolling p late (z axis direction of FIG. 19).

The overlapped expanded side portion 1042 prevents bending in a reversedirection based on a neutral surface where the display unit 151 isarranged by restricting an angle between adjacent unit rolling plates(unit elements comprised of the support bar 1041, the expanded sideportion 1042 and the slide protrusion 1043).

When the third contact surface 10423 and the fourth contact surface10424 are in surface contact with the first contact surface 10421 andthe second contact surface 10422, bending deformation may be made at acurved portion. The third contact surface 10423 may include a curvedportion extended from the first contact surface 10421 to a curve, andthe fourth contact surface 10424 has an angle of 90° or more with thesecond contact surface 10422.

Since the third contact surface 10423 includes a curved surface, thethird contact surface 10423 and the fourth contact surface are in linecontact with each other. The curved portion of the third contact surface10423 moves along the fourth contact surface 10424 at a portion wherethe rolling plate 104 is bent, whereby the contact portion between thethird contact surface 10423 and the fourth contact surface 10424 may bevaried. Since the fourth contact surface 10424 forms an angle greaterthan 90° with the second contact surface 10422, the third contactsurface 10423 and the fourth contact surface 10424 may be in contactwith each other even in a curve portion.

A position where the third contact surface 10423 and the fourth contactsurface 10424 adjoin each other may be varied as the rolling plate 104is bent, and at the same time the contact state between the thirdcontact surface 10423 and the fourth contact surface 10424 may bemaintained. The angle between the unit rolling plates may be restrictedto be changed within only a limited range, whereby a bump may beprevented from being generated in the display unit 151 due to reversebending.

The end portion of the support bar 1041 may be exposed through the guidegroove 10427. The guide protrusion 10426 of adjacent unit rolling platesmay adjoin the end portion (the fifth contact surface 10425) of theexposed support bar 1041. Movement of the unit rolling plate in a thirddirection may be restricted (y axis direction of FIG. 19) through thefifth contact surface 10425, whereby the unit rolling plate may stablyslid in only the first direction.

FIG. 20 is an exploded perspective view illustrating a layer structureof the rolling plate 104 and the display unit 151 of the mobile terminal100, FIG. 21 is a view illustrating a pattern of a non-expanded sheet1047 and the rolling sheet 1045, and FIG. 22 is a view illustrating asection of the layer structure of FIG. 20.

A lower side of FIG. 20 is a front direction where the display unit 151is arranged, and an upper side of FIG. 20 is a rear direction of thedisplay unit 151, and is a portion toward the inside of the second frame102.

As described above, the length of the rolling plate 104 should bedownsized in the rear direction of the display unit 151 based on thedisplay unit 151 at the curved portion and is expanded outwardly. Thatis, the support bar 1041 may include a front surface adjoining thedisplay unit 151 and a rear surface opposite to the front surface,wherein the front surface may be expanded and the rear surface may becontracted. If the support bar 1041 is expanded from the rear surface,the aforementioned reverse bending occurs. Therefore, the non-expandedsheet 1047 may be attached to the rear surface of the support bar 1041such that reverse bending may not be generated on the rear surface ofthe support bar 1041.

As illustrated in FIG. 20, the non-expanded sheet 1047 may not need tobe formed in an entire area in the third direction of the rolling plate104 but partially be arranged. Two or more non-expanded sheets 1047 longin the first direction may be spaced apart from each other in the thirddirection to prevent reverse bending of the rolling plate 104 fromoccurring.

When the rolling plate 104 is arranged in the curved portion rolled inthe roller, the non-expanded sheet 1047 may be contracted in accordancewith the angle change of the rolling plate 104 but is not expanded toprevent reverse bending from occurring. The non-expanded sheet 1047 mayinclude a metal material so as not to be stretched, and a plurality ofholes may be formed at a bent portion that may be bent at the curvedperiod, to facilitate bending deformation.

Referring to FIG. 21, a solid portion 1047 a having no deformation maybe arranged in a portion of the non-expanded sheet 1047, which isoverlapped with the support bar 1041, and a bending portion 1047 b wherebending deformation may occur may be arranged in a portion of thenon-expanded sheet 1047, which is arranged between the support bars1041. That is, the solid portion 1047 a and the bending portion 1047 bmay alternately be arranged in the first direction, and the solidportion 1047 a may directly be attached to the support bar 1041 and thebending portion 1047 b is not attached to the rolling plate 104.

An adhesive tape 1047 c for attaching the non-expanded sheet 1047 to thesupport bar 1041 may be arranged in only a position corresponding to thesolid portion 1047 a (see FIG. 21(b)). The bending portion 1047 b of thenon-expanded sheet 1047 may maintain a floated state without beingdirectly attached to the support bar 1041.

The bending portion 1047 b of the non-expanded sheet 1047 may beimplemented in the form of a mesh where a plurality of holes are formedin a metal sheet. The non-expanded sheet 1047 includes a continuousportion continuously extended from the bending portion 1047 b in thefirst direction without holes, wherein a length of the continuousportion is fixed and therefore the non-expanded sheet 1047 is notstretched in the first direction.

However, the holes may lower density of the bending portion 1047 b tocause bending deformation, and may be inserted between the support bars1041 when the rolling plate 104 is bent as shown in FIG. 22(b), wherebythe length of the non-expanded sheet 1047 in the first direction may becontracted.

The rolling sheet 1045 shown in FIG. 21(c) is arranged between thedisplay unit 151 and the support bar 1041 and provided with holes formedin a zigzag shape. Since the holes are formed without being continuouslyconnected in the first direction, the rolling sheet 1045 may bestretched or contracted in the first direction.

Since the holes of the non-expanded sheet 1047 are not arranged in azigzag shape, the non-expanded sheet 1047 includes a continuous portionprovided with holes that are not arranged in the first direction,whereby the non-expanded sheet 1047 may not be stretched in the firstdirection. However, since the holes of the rolling sheet 1045 arearranged in a zigzag shape, the length of the rolling sheet 1045 may bechanged in the first direction.

The non-expanded sheet 1047 may prevent reverse bending of the rollingplate 104 from occurring, thereby assisting the display unit 151 toslidably move by maintaining the display unit 151 at a flat statewithout bending.

As described above, the mobile terminal 100 of the present disclosuremay adjust the size of the screen as needed and therefore satisfyportability and usability.

Also, since the rolling plate 104 supporting the display unit 151 is nottwisted by rotation, the display unit 151 may maintain the flat state.

Also, since the movement of the rolling plate in the thickness directionand the third direction is restricted, the state of the mobile terminal100 may stably be changed.

As the present features may be embodied in several forms withoutdeparting from the characteristics thereof, it should also be understoodthat the above-described embodiments are not limited by any of thedetails of the foregoing description, unless otherwise specified, butrather should be considered broadly within its scope as defined in theappended claims, and therefore all changes and modifications that fallwithin the metes and bounds of the claims, or equivalents of such metesand bounds, are therefore intended to be embraced by the appendedclaims.

What is claimed is:
 1. A mobile terminal comprising: a displaysubjectable to bending deformation upon moving in a first direction; anda rolling plate attached to a rear surface of the display to enablebending deformation corresponding to the bending deformation of thedisplay, wherein the rolling plate includes: a plurality of support barsextending along a second direction perpendicular to the first directionand arranged in parallel with respect to the first direction, whereineach of the plurality of support bars includes an expanded side portionarranged at an end portion of the support bar, and wherein the expandedside portion of each of the plurality of support bars includes a guideprotrusion protruding toward the expanded side portion of an adjacentsupport bar, and a guide groove arranged opposite to the guideprotrusion, corresponding to the guide protrusion of the expanded sideportion of a second adjacent support bar, wherein the guide protrusionof the expanded side portion of each of the plurality of support barsincludes a first contact surface and a third contact surface, whereinthe guide groove of the expanded side portion of each of the pluralityof support bars includes a second contact surface that adjoins the firstcontact surface of the expanded side portion of the second adjacentsupport bar, a fourth contact surface that supports the third contactsurface of the guide protrusion of the expanded side portion of thesecond adjacent support bar in a thickness direction, and wherein anangle between the fourth contact surface and the second contact surfaceof the guide groove of the expanded side portion is more than 90°. 2.The mobile terminal of claim 1, wherein the third contact surface of theguide protrusion of the expanded side portion of each of the pluralityof support bars includes a curved portion extending from the firstcontact surface.
 3. The mobile terminal of claim 1, wherein at least aportion of the end portion of each of the plurality of support bars isexposed through the corresponding guide groove, and the exposed portionof the end portion of the support bar is covered by the guide protrusionof the expanded side portion of the second adjacent support bar.
 4. Themobile terminal of claim 3, wherein the end portion of each of theplurality of support bars includes a fifth contact surface that adjoinsthe guide protrusion of the expanded side portion of the second adjacentsupport bar.
 5. The mobile terminal of claim 1, further comprising: afirst frame; a second frame slidably moveable with respect to the firstframe in the first direction, to switch from a first state to a secondstate; and a slide frame moveable in the first direction with respect tothe second frame when the second frame moves in the first direction,wherein the display includes: a first area coupled to the first frame; asecond area coupled to the slide frame; and a third area arrangedbetween the first area and the second area and bent to surround thesecond frame.
 6. The mobile terminal of claim 5, wherein the secondframe further includes: a side portion arranged in the second direction;and a slide rail formed at the side portion, wherein the rolling platefurther includes a slide hook protruding from the expanded side portionof each of the plurality of support bars and inserted into the sliderail, and wherein the slide hook is moveable along the slide rail inaccordance with the movement of the second frame in the first direction,and has an oblong shape longer in an extension direction of the sliderail than a width direction of the slide rail.
 7. The mobile terminal ofclaim 1, wherein the expanded side portion of each of the plurality ofsupport bars has a width that becomes more narrow as it is spacedfurther from the display.
 8. The mobile terminal of claim 1, wherein therolling plate further includes a non-expanded sheet coupled to a rearsurface of the plurality of support bars.
 9. The mobile terminal ofclaim 8, wherein the non-expanded sheet includes: a solid portionattached to the plurality of support bars; and a bending portionarranged between the support bars, wherein the bending portion isinserted between the support bars during the bending deformationcorresponding to the bending deformation of the display.
 10. The mobileterminal of claim 9, wherein the non-expanded sheet includes a metalmaterial, and the bending portion has a mesh form provided with aplurality of holes.
 11. The mobile terminal of claim 9, furthercomprising an adhesive tape for attaching the non-expanded sheet to thesupport bars, wherein the adhesive tape is arranged at a positioncorresponding to the solid portion.
 12. The mobile terminal of claim 1,further comprising a rolling sheet arranged on the rear surface of thedisplay, wherein the rolling sheet is provided with a plurality of holesextending along the second direction.
 13. A mobile terminal comprising:a display subjectable to bending deformation upon moving in a firstdirection; and a rolling plate attached to a rear surface of the displayto enable bending deformation corresponding to the bending deformationof the display, wherein the rolling plate includes: a plurality ofsupport bars extending along a second direction perpendicular to thefirst direction and arranged in parallel with respect to the firstdirection; and a non-expanded sheet coupled to a rear surface of theplurality of support bars, wherein each of the plurality of support barsincludes an expanded side portion arranged at an end portion of thesupport bar, wherein the expanded side portion of each of the pluralityof support bars includes a guide bump engaged with the expanded sideportion of an adjacent support bar, wherein the non-expanded sheetincludes: a solid portion attached to the plurality of support bars; anda bending portion arranged between the support bars, and wherein thebending portion is inserted between the support bars during the bendingdeformation corresponding to the bending deformation of the display. 14.The mobile terminal of claim 13, wherein the non-expanded sheet includesa metal material, and the bending portion has a mesh form provided witha plurality of holes.
 15. The mobile terminal of claim 13, furthercomprising an adhesive tape for attaching the non-expanded sheet to thesupport bars, wherein the adhesive tape is arranged at a positioncorresponding to the solid portion.